Manufacture of plates and sheets.



UNITED STATES PATENT OFFICE:

DAVID S. BROOKMAN, 0F WELLSVILLE, OHIO, ASSIGNOR TO AMERICAN SHEET & TINPLATE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEW PatentedNov. 30, 1909.

JERSEY.

MANUFACTURE OF PLATES AND SHEETS.

941,854.. Specification of Letters Patent.

N 0 Drawing. Application filed March 20, 1909.

Serial No. 484,793.

To all whom it may concern:

Be it known that I, DAVID S. BROOKMAN, of lVellsville, in the county ofColumbiana and State of Ohio, have invented a new and useful Improvementin the Manufacture of Plates and Sheets, of which thefollowing is afull, clear, and exact description.

My invention has relation to the manufacture of metal plates and sheetsand is designed to provide a novel method of treatment, whereby theplates are given a polished oxidized blued surface or finish of superiorcharacter.

A further object of the invention is to provide a method of thischaracter which will materially reduce the number of steps of operationswhich have heretofore been necessary for the production of a finish ofthis character, thereby materially reducing the time, labor and cost ofmanufacture and correslpondingly increasing the output of the m1 A stillfurther object is to provide a method by which the finished plates orsheets will be perfectly flat and free from warping or buckling, such ashas been experienced heretofore in the manufacture of this class ofplates and sheets.

In accordance with my invention, I take the plates or sheets which havebeen hot rolled in the usual manner and place them in an annealing boxand bring them up to an annealing temperature. The box with thecontained plates or sheets is then removed from the furnace and steam isintroduced to produce an oxidizing atmosphere,

while the plates are cooling. The resulting oxidation of the platesproduces what is known as a steam blued finish, and the cold plates orsheets are then given one or more cold roll passes, one being usuallysufficient. They are then again annealed and allowed to partially coolin the annealing box out of contact with the atmos )here. They are thenin their partially coole state and preferably at a temperature of about300 F. to 1000 F passed through one or more stands of polishing rolls,being further cooled during this operation. After they are cold, theyare then given a final finlshing cold roll pass. The effect of this coldfinishing pass is to remove all buckling or warping produced by the warmpass, and giyes a perfectly fiat sheet with a highly polished uniformblued finish.

I claim:

In the manufacture of plates or sheets,-

my hand.

DAVID S. BROOKMAN. Witnesses:

F. L. WELLS, W. R. MACDONALD.

